题目

Her work is often very hard and she gets very tired. The work is _____.         A.wonderful                  B.splendid                  C.tedious                  D.magnificent   答案：C如图，已知第一象限内的点A在反比例函数y=上，第二象限的点B在反比例函数上，且OA⊥OB，tanA=，则k的值为（ ）A．-2 B．4 C．-4 D．2